Astronauts face a topsy-turvy world, where up and down is nowhere to be found. Sensors in your inner ear signal to the brain not only that you’re not in Kansas anymore, but that the familiar tug of Earth’s gravity is missing. Very few astronauts have what’s called “lead head” — an immunity from space sickness, which causes vertigo, nausea, headaches and sometimes vomiting. Treatment with medications during the early flight days of a space mission is common, though NASA continues to search for the best way to counter space sickness. Everything from drugs to yoga and biofeedback remain on the table. Scientists still don’t understand the underlying physiology, and getting a handle on what’s behind space sickness hasn’t been easy. For one, astronauts in the past didn't like notifying ground control that they were busy wiping their bravado off the spacecraft walls because they were paranoid that reporting less than top-notch well-being might spoil their chances at another trip into space. Experienced crew members tend to reduce their head movements, at least for the first 2-4 days. Unfortunately, some of the best drugs carry with them some risks of either sedation or blurred vision. What plagues researchers now is how something like space sickness is going to go over when space tourism becomes a reality.
